Intersubband absorption at 1.5-3.5 um in GaN/AlN multiple quantum wells grown by molecular beam epitaxy on sapphire
Journal article, 2007

Ten and twenty period multiple quantum well structures with 1.5-5.4 nm GaN wells and 1.2-5.1 nm AlN barriers were grown on sapphire by molecular beam epitaxy. Layer thicknesses were determined by X-ray diffraction measurements and simulations. Reciprocal space mapping showed that the relaxation of the quantum well layers was independent of the buffer layer thickness. Intersubband absorption was observed by Fourier transform infrared spectroscopy at 1.5-3.5 m. Monolayer fluctuations in the quantum well width induced multiple peaks in spectra, which were well fitted to Lorentzian peaks of only 57 meV linewidth. Samples were very homogeneous as the absorption peak energy varied less than 1% along 4 cm on 2 inch wafers. The intersubband transition energies were calculated considering the conduction-band nonparabolicity, built-in fields, strain, and many-body effects. The calculation and comparison to the fitted Lorentzian peak energies indicated a moderate blueshift due to many-body effects. It was shown by both experiments and calculations that the AlN barrier width affects the intersubband transition energy

68.65.Fg 73.21.Fg 78.30.Fs 78.67.De 81.07.St 81.15.Hi


Xinju Liu

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Petter Holmström

Royal Institute of Technology (KTH)

Sophia University

Peter Jänes

Royal Institute of Technology (KTH)

Lars Thylén

Royal Institute of Technology (KTH)

Thorvald Andersson

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Physica Status Solidi (B): Basic Research

0370-1972 (ISSN) 1521-3951 (eISSN)

Vol. 244 8 2892-

Subject Categories

Condensed Matter Physics



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